TetGen example: Dragon

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The dragon, a symbol of Chinese culture. The source data (reconstructed surface mesh ) can be found in The Stanford 3D Scanning Repository, also at Georgia Institute of Technology's Large Geometric Models Archive. The data size is huge (566,098 vertices, 1,132,830 triangles). Luckily, the one shown below can be downloaded from Inria's Free 3D Meshes Download page. The size is much smaller.

The input surface mesh, 21104 nodes, 41964 triangles.

The constrained Delaunay tetrahedralization, 22847 nodes, 74922 tetrahedra, and 44964 boundary faces.
The quality Delaunay tetrahedralization (Statistics).

Runtime output and mesh quality statistics

[si@a302n3]# ~/tetgen-dbg/tetgen -pqV dragon-50,010.smesh
Opening dragon-50,010.smesh.
Constructing Delaunay tetrahedrization.
  Total flips: 898786, where T23 543115, T32 355671, T22 0, T44 0
Delaunay seconds:  10.08
Creating surface mesh.
  Constructing mapping from indices to points.
  Unifying segments.
  Constructing mapping from points to subfaces.
  Merging coplanar facets.
Perturbing vertices.
  Constructing mapping from points to tetrahedra.
  0 break points are inserted.
Delaunizing segments.
  Marking segments have acute corners.
  Constructing mapping from points to segments.
  Constructing mapping from points to tetrahedra.
  25952 protect points are inserted.
Constraining facets.
  Constructing mapping from points to tetrahedra.
  The biggest cavity: 22 faces, 13 vertices
  Enlarged 0 times
Segment and facet seconds:  13.37
Removing unwanted tetrahedra.
  Marking concavities for elimination.
  Marking neighbors of marked tetrahedra.
  Deleting marked tetrahedra.
Hole seconds:  0.57
Removing degenerate tets.
  0 degeneracies are removed.
Repair seconds:  0.18
Adding Steiner points to enforce quality.
  Marking sharp subfaces.
  806 subfaces have been marked.
  Marking skinny subfaces.
  41395 subfaces have been marked.
  Initializing protecting spheres.
  Constructing mapping from points to tetrahedra.
  Splitting encroached subsegments.
  327012 points are inserted.
  Splitting encroached subfaces.
  87125 points are inserted.
  Splitting bad tetrahedra.
  451977 points are inserted.
  Removing slivers.
  19044 slivers are removed.
  67 sliver(s) survived.
  146 points are inserted.
  Total 866260 points are inserted.
Quality seconds:  2124.14
 
Writing dragon-50,010.1.node.
Writing dragon-50,010.1.ele.
Writing dragon-50,010.1.face.
 
Output seconds:  12.84
Total running seconds:  -2133.79
 
Statistics:
 
  Input points: 50010
  Input facets: 100040
  Input holes: 0
  Input regions: 0
 
  Mesh points: 942222
  Mesh tetrahedra: 3843078
  Mesh faces: 8308678
  Mesh subfaces: 1245336
  Mesh subsegments: 663264
 
Mesh quality statistics:
 
  Smallest volume:       9.7226e-09   |  Largest volume:            11697
  Shortest edge:           0.001022   |  Longest edge:             61.517
  Smallest dihedral:       0.078977   |  Largest dihedral:       179.8633
 
  Radius-edge ratio histogram:
         < 0.707     :     33962      |    1.6 - 1.8        :    293726
   0.707 - 1         :    982103      |    1.8 - 2          :    142219
       1 - 1.1       :    487318      |      2 - 2.5        :     35400
     1.1 - 1.2       :    474786      |    2.5 - 3          :     15942
     1.2 - 1.4       :    814193      |      3 - 10         :     27362
     1.4 - 1.6       :    534521      |     10 -            :      1546
  (A tetrahedron's radius-edge ratio is its radius of circumsphere divided
    by its shortest edge length)
 
  Aspect ratio histogram:
  1.1547 - 1.5       :         0      |     15 - 25         :     46837
     1.5 - 2         :         0      |     25 - 50         :      7966
       2 - 2.5       :        39      |     50 - 100        :       563
     2.5 - 3         :     74598      |    100 - 300        :       168
       3 - 4         :    867452      |    300 - 1000       :        15
       4 - 6         :   2121883      |   1000 - 10000      :         4
       6 - 10        :    622929      |  10000 - 100000     :         0
      10 - 15        :    100624      | 100000 -            :         0
  (A tetrahedron's aspect ratio is its longest edge length divided by the
    diameter of its inscribed sphere)
 
  Dihedral Angle histogram:
       0 - 10 degrees:     68166      |     90 - 100 degrees:    695614
      10 - 20 degrees:    334808      |    100 - 110 degrees:    884078
      20 - 30 degrees:    983070      |    110 - 120 degrees:    752756
      30 - 40 degrees:   1160238      |    120 - 130 degrees:    481053
      40 - 50 degrees:    837180      |    130 - 140 degrees:    279815
      50 - 60 degrees:    409134      |    140 - 150 degrees:    163749
      60 - 70 degrees:     50479      |    150 - 160 degrees:     99296
      70 - 80 degrees:     21980      |    160 - 170 degrees:     53642
      80 - 90 degrees:    410609      |    170 - 180 degrees:       489
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Hang Si